


Under Your Skin

by raidelle



Category: Final Fantasy XV
Genre: Alternate Universe - Soulmates, M/M, Mentions of Sex, Soulmate-Identifying Marks
Language: English
Status: Completed
Published: 2018-12-22
Updated: 2018-12-22
Packaged: 2019-09-24 20:37:08
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,932
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17107718
Author URL: https://archiveofourown.org/users/raidelle/pseuds/raidelle
Summary: In an Eos where soul marks appear on one's body when their soulmate is born, Nyx gets an intricate pattern on his back when he's ten years old.He spends years looking, until he's almost finally given up. And then Ignis Scientia asks him for help with weapons training and the world tilts.





	Under Your Skin

**Author's Note:**

  * For [morrezela](https://archiveofourown.org/users/morrezela/gifts).



> This will probably evolve into a series in the near future.
> 
> Right now, though, I hope you enjoy this story. This is my first time both writing a soulmate AU and participating in a gift exchange, so I'm quite excited for this one. :) 
> 
> Happy Holidays!

Nyx Ulric doesn't realize his soul mark -- an intricate pattern of interwoven tendrils of lightning and flame across his upper back -- has appeared until Libertus points it out to him one sunny and crisp winter day. 

“Whoa, dude!” Libertus exclaims. “Where'd you get that?” They're about to take a dip into the icy-cold Galahdian River, in direct defiance of both their mothers’ orders, and Nyx has just taken his shirt off to toss it haphazardly onto the rocky banks. 

“Get what?”

“That!” Libertus prods the design with an index finger. “‘M gonna tell your mom! You know we're not allowed to get any tattoos until we're thirteen!”

“The fuck're you talkin’ about? I don't have any tattoos!” Nyx twists in a vain attempt to see what Libertus is looking at.

“That!” Libertus almost yells as he prods Nyx's back again. “It looks so cool! Why didn't you tell me you're gonna get one? Man, I'm so jealous!” He pouts for a moment then runs toward the river at full tilt. He looks over his back and calls with a wicked grin. “I'm still tellin’ Missus Ulric though!”

Nyx chases after Libertus, yelling, “Fuck you, man! I don't have any tattoos!” 

Later that afternoon, shivering under two fleece blankets and teeth chattering, Nyx stutters an apology to his mother. 

“I really -- r-really d-dunno how… how it got there, Mom. S-s-sorr-y.”

His mother sighs, fond and exasperated and a touch sorrowful. “You've nothing to be sorry for.” She runs a fine-toothed comb through Nyx's hair and redoes the short braids with a light-handed touch. “I know it's not a tattoo because no one in their right Galahdian mind would do it. And you might be a bit of a firecracker but I know this is one rule you aren't going to break.” She raises an eyebrow at her son with a little laugh.

Nyx laughs back, shaky from the cold and a tiny bit of guilt. “So it’s… what is it?”

“It's your soul mark, honey.”  


**********

  
Somewhere in Eos much later still that night, a newborn cries with a voice full and clear as tolling bells. Plumes of flame and forks of lightning sear themselves in dark, mystical ink across the infant's back.

Miles away, ten-year-old Nyx mutters in his sleep and dreams of warm arms enveloping him in an embrace that feels so much like home.  


* * *

  
Twenty years and a handful real tattoos later, Nyx Ulric still hasn't found whoever shared his soul mark. It's not an urgent thing, if he were being honest with himself, but it goes against his very nature to not know all there is to know about his life and his circumstances.

He also feels an odd sense of disconnection with his Galahdian heritage the longer the identity of his soulmate eludes him. They’re a tight-knit community steeped in age-old traditions and it's rare that someone got soul-bound to an outsider, much less someone considerably younger. Even his mother, who was as unorthodox as a Galahdian woman could get, got her soul mark -- blue-gray deer antlers that encircled her wrist -- when she’d been about to turn five, on a stormy summer night when his father had been born in a small seaside town on the other side of Galahd.

And then there’s the case of Libertus, whose left arm suddenly got covered by a blooming jasmine vine all those years ago when Selena took her first breath and screamed her lungs out to declare her arrival, an identical mark already adorning her tiny, wrinkly limb.

Libertus's soul mark had long since faded into light red lines like lightning-strike scars, on the same day that Niflheim struck and occupied Galahd. He'd never been the same after; Nyx has tried, time and again, to give a name to the ever-present dark cloud that hung over his best friend’s head. It's not grief or unrestrained anger, like what he himself felt for long months after that fateful day, it's… something more. Maybe because losing a sister is so much more different than losing the other half of your soul. 

Nyx sighs as he closes the door of his locker and bangs his head on it. This is what he gets when he slacks off during training -- his body doesn't get tired enough and his brain decides to fire up all kinds of sentimental thoughts.

Then again, he supposes that the Astrals owe it to him, after everything he's done for the King and the Crystal in the past decade, to at least let him _see_ his soulmate. It doesn't even matter anymore if they aren't Galahdian, which they most likely are because as far as he knows, every surviving Galahdian have been accounted for and none of them bear his soul mark. He'd even welcome it even if they're in a relationship with someone else. Nyx just wants to know something more about whoever it is, other than that they’re “ten years younger” and “still alive.”

He gets shaken out of his musings when an accented voice rings from behind him.

“Nyx Ulric?”

“What?” he says rather abruptly. He turns and leans back against the lockers, and finds himself face to face with one advisor to the Prince of Lucis not five feet from him.

“Oh, I'm sorry if I startled you but I --” 

Nyx snorts. “‘Startled.’ Haven't heard that word in a while. Ignis Scientia, right?”

“Yes. How did you --” 

“I’ve seen you around. Also, it’s kinda part of my job to know who's who around here,” he shrugs. “And no, you didn't _startle_ me.”

Ignis smiles, if Nyx could even call the tiny upturn of lips a smile. “Of course not,” he says agreeably.

“So what brings you to my figurative doorstep this fine evening?”

Ignis visibly girds himself, as if preparing for an argument. “Well,” he begins, drawing the word out. He squares his shoulders and clears his throat.

The actions draw Nyx's attention to said body parts, and there's a flash of _something_ in his gut. He shakes his head in a small motion and forces himself to pay proper attention to Ignis. 

“I was merely wondering if you'd be willing to work with me on my weapons training. There's no one in the Crownsguard proficient enough with daggers --”

“What about Monica?” Nyx asks. He'd seen Cor's second-in-command during a couple of field exercises and exhibition matches, and Nyx has to admit that she's quite vicious with her twin blades. 

“No offense to Miss Elshett but…” Ignis trails off, looking around as if checking if Monica's around. He turns back to Nyx with an arched brow. “I want to train with the best. And I think even she would agree with me that that’s _you_.”

“Way to stroke my ego, Scientia,” Nyx replies, a playful grin curling his lips.

“Is it working?” Ignis grins back at him.

“A little bit, yeah.” He tilts his head to the side and gives Ignis a sly look. “What do I get if I say yes?”

“Really?” Ignis raises his eyebrow again, this time with a wry expression.

Nyx merely shrugs, then crosses his arms on his chest. He's probably getting the better end of the deal, what with his goal of purging his brain of all unnecessary thoughts by tiring himself out, but he doesn't need to let Ignis know his ulterior motives. 

Ignis, for his part, has taken on a serious, contemplative expression. It looks to Nyx as if he's trying to predict all the possible outcomes, and all of them were unfavorable.

Finally, Ignis clears his throat. “Alright, I think I know what --” 

Nyx doesn't know what came over him at that moment, but he finds himself blurting out two words that shock the both of them. “A date.” 

“Excuse me?” 

Nyx has half a mind to walk the words back, to pretend that he didn't just ask Ignis Scientia for a date in exchange for weapons training. But there's an odd sensation in the back of his chest, like something is tugging him forward, and it makes him soldier on.

He looks at Ignis’s expectant green eyes and braces himself. “A date,” he says, more slowly and clearly this time. “I'll train with you if you promise to go out on a date with me.”

Ignis gives him a long searching look before saying, “Does this date have to happen before or after?”

Now _that_ is unexpected, Nyx muses, and it takes him a few seconds to reply. “You know what, I'm feeling generous. Let's get training out of the way first.”

Ignis hums his approval. “And do I get to choose when and where this date would happen?”

“Nope.” Nyx pops the ‘p’ and shakes his head for emphasis. “I'm the one who asked you out so I'm gonna call the shots, yeah?” 

“All right,” Ignis nods. “And do we have to go on a date after every training session?”

Nyx can't help his answering puff of incredulity. “Are you always this thorough?”

“Yes,” Ignis says simply.

“Okay, fine. Y'know what? Just give me the one date and then you can decide if you want to go on another. Deal?” He extends a hand for Ignis to shake.

Ignis eyes him carefully again with those brilliant greens before shaking his proffered hand with a firm grip. “Deal.”

Nyx registers several feelings all at once: the warmth of the palm against his, a little on the soft side but with budding calluses. The phantom of an electric tingle skittering up his arm. His heartbeats slowing down to a relaxed cadence. His blood flowing in his veins like a living, roaring thing.

Each sensation is so strong and so distinct, crashing into him all within the span of a few seconds. The potent combination makes him a little dizzy and he has to shake his head so he can start processing what's happening.

“I'll see you at two in the afternoon on Thursday then, Mister Ulric,” he hears Ignis say, snapping him out of his trance.

“ _Mister_ Ulric?” He barely contains his sniff at the propriety. “Nah, I'm just Nyx.”

“Of course, Nyx,” Ignis nods, and an odd thrill rushes through him. “Thursday at two, then?”

“Why am I not surprised that you know when's my free time?” He shakes his head again, this time in mild amusement. “Yeah, sure. I'll be here.”

“Excellent. I'm looking forward to it, Nyx, thank you.”

“Sure, me too.”  


* * *

  
Nyx's Thursday afternoons usually had him going to Little Galahd, sitting under the great oak in the park and holding a spiced garula skewer, a can of beer, or both. Sometimes, he and Libertus would get a quick lunch together; sometimes he would let Crowe treat him to a movie or a fancy cup of coffee. 

Today, Nyx is warming up for a training session with Ignis Scientia. He doesn't know yet how much experience or natural skill the young advisor has; he doesn't even know if they're sparring with real daggers. But Ignis is expecting “the best” and Nyx is determined to deliver, so… warm ups.

He's going through a series of knife-fighting drills when Ignis arrives, looking unusually casual in a dark gray running jacket with a gray Crownsguard tank top underneath, and black workout pants. His usual briefcase is absent, replaced by a green duffel bag with a white logo of the Crown City Royals emblazoned on the front pocket.

“Hello,” Ignis says. “You’re early.”

“I didn’t want to be late.” Nyx wishes he sounds nonchalant even through his inexplicable nerves. It isn’t his first time to give a one-on-one, much less train with a Crownsguard (Gladiolus Amicitia is a tenacious bastard), so he doesn’t understand where the anxiety is coming from. Which means the anxiety is so much worse.

He sighs before banishing his kukris back into the Armiger, then cracks his neck before giving Ignis his full attention. “You need a few minutes to stretch or whatever?”

“Yes, please,” Ignis says.

“I just realized that I don’t know your skill level yet. Have you started handling the real thing?” Nyx asks. He tries and fails to keep his eyes averted as Ignis removes his jacket. All those times he’d seen the young Crownsguard walking around the Citadel, he’d always been wearing perfectly tailored semi-formal attire; most of the time, he’d even be wearing gloves. Nyx supposes it’s the unusualness of seeing Ignis in gym clothes that keeps him riveted.

“I’ve only just finished the prescribed training with blunted weapons,” Ignis tells him as he slips off his jacket. “Otherwise, the only thing I’ve done with my official-issue daggers is pick them up from the armory and test the heft and balance.”

“Okay,” Nyx nods. “I can work with that.”

Ignis smiles. “I know.” He folds his jacket over his arm and hikes his bag higher up his shoulder. “Let me just put my things away and we can get started.”

Nyx nods again, following Ignis’s progress toward the bleachers. His eyes roam appreciatively over the slender neck, the lean and slightly muscled arms, the strong back that…

He’d never used the King’s magic for frivolous reasons, ever, no matter how tempting it is to just warp from his apartment to the corner store or keep his beer perpetually cold with a tightly controlled blizzard spell.

He tapped on that well of magic now, almost involuntarily, to close the few feet between him and Ignis. It was the shortest distance he’s ever warped and it makes him reel, stumbling forward and knocking Ignis off his feet.

Ignis grunts in pain and surprise. “What the f--” He wiggles to get Nyx off his back.

“Sorry, sorry, sorry!” Nyx says, panicked. He scrambles to stand, getting his legs tangled with Ignis’s in the process. “I just… I just…”

“You just what? What happened?”

“It’s just… Your back.”

Ignis furrows his eyebrows at him. “My back?”

“I saw… I mean, the, uh…”

“Oh,” Ignis says in realization. “My soul mark? What about it? Don’t tell me you haven’t seen one before.”

Nyx laughs nervously. “Of course I have. It’s just that I… I haven’t ever seen one that looks exactly like mine,” he says in a voice weak with something he could only describe as shattering disbelief. 

“I'm sorry?” Ignis sounds a little shocked himself. “You're saying that you're… my soulmate?”

Nyx wonders at the hint of derision in Ignis's voice. Is it because it's _him_ and not a titled and landed Lucian lady? “Yes,” he says with a small nod. “May I see it? Please?” After two decades, Nyx is not above begging. Not anymore. 

“What?” Now Ignis looks scandalized. 

“Your… Our soul mark. Please, may I see it?” Nyx has to close his fists tight to stop himself from surging forward and ripping Ignis's tank top off. 

“No. I… It's not --” 

“Here,” Nyx pulls off his shirt and turns his back to Ignis.

“That's… You've only seen my shoulder blades and not… How can you even --”

Nyx laughs, desperate and incredulous. “I have a photo blown up and printed, stuck to the inside of my closet at home. I have a smaller one on the door of my locker here. I've been looking at those pictures for years, so I damn well know what it looks like. Every single fucking detail.”

“I… I'm not…”

But Ignis couldn't tell Nyx what he's not. He walks out of the training hall, stiff and silent as the Prince in social functions, and leaves Nyx to stare at the empty doorway long after the sound of his clipped footsteps have faded.  


* * *

  
“I just can't --”

“Believe it's him, yeah, you said that about seven times now.” Crowe throws back another swallow of beer. She sounds sympathetic but also quite impatient. “You also said about seven thousand times before that it doesn't matter who your soulmate is as long as --” 

Nyx cuts her off with a look and she raises her hands in surrender.

“Look, man, I don't know what you want us to say,” Libertus says. “D'you want us to tell you that it's okay being soul-bound to a non-Galahdian? Because it is.”

“I know it is! It's just that I --”

“Ignis is a pretty great guy,” Crowe says reasonably. “I worked with him a few times, got to talk to him and hang out for a bit. He's a little intense about getting all the details just right --” 

Nyx huffs a little laugh at that. “Yeah, I noticed.”

Crowe nods. “And he's a little too composed, sometimes, it's borderline unnatural. But other than that, he's really thoughtful and sweet. Real good-looking, too.”

“I don't need a list of his best qualities, Crowe,” Nyx says through gritted teeth. 

She raises both hands again in a placating gesture. “I'm just saying.”

“You said he already agreed to go on a date with you, right?” Libertus asks. 

“Yeah.”

“Then go,” Libertus says simply. “You can think about everything else later.”

“Look at you, being all wise and stuff.” Crowe's voice is lightly teasing and Libertus throws a balled up napkin at her. She turns back to Nyx with a small smile. “You know you're not, like, contractually obligated to be romantically involved with your soulmate, right?”

“I know that!” Nyx winces at how petulant he sounds. “But I --” 

“Just go on that date, Hero,” Libertus tells him with finality. “Give it a chance. Not everyone gets to meet their soulmate, much less be with them forever.”

The soft, pained smile that Libertus gives him is what makes Nyx say yes.  


* * *

  
A week later, Nyx is back in the training hall, fully dressed in his Kingsglaive garb and stalking purposefully to where Ignis is going through drills with Monica. He deliberately puts himself in Ignis's line of sight, and he takes a small measure of comfort at the small nod that Ignis throws at his direction.

He allows himself a few moments to admire Ignis's form. He looks a bit tense, holding his daggers a little too tightly judging by the tendons standing out on his knuckles, but that's probably because of his presence anyway. Otherwise, he couldn't fault the textbook-perfect stance. 

“Monica,” he says finally. “Could I borrow Ignis for a sec?”

She gives him an arch look and Ignis gives her a placating one. “It's fine, Monica,” Ignis tells her. 

With a tight nod, Monica says, “Good work today. I'll see you same time next week?” 

Instead of answering, Ignis gives Nyx a look as if to ask, “Am I?” The look prompts Monica to turn her eyes on him, too, and Nyx belatedly realizes that they're silently asking him if he's going to be taking over Ignis's training moving forward. 

“Oh,” he finally says. “I, uh… I think we should continue this um, arrangement for at least the coming week. I need to clarify a few things with Ignis first.”

Monica gives another small, curt nod. “Same time next week, then.” With no further words, she turns on her heel to leave. Her daggers vanish into the Armiger in a shower of blue sparkles.

A few awkward heartbeats pass before Ignis puts him out of his misery. “Well…” he begins with a deep breath. “I don't exactly know why you've come to see me, but I think I have an idea.” He smiles a little ruefully. “And it's quite fortunate because I wanted to see you, too, because I've been wanting to apologize and --”

“Yeah, me too. I kinda went overboard last time. I mean…” Nyx shrugs. “I guess it was just the shock of seeing my soul mark on someone else after I've sort of given up on it.”

“And I shouldn't have reacted that way. It was quite understandable, the way you acted. I think.” Ignis's brows furrow at the last two words. “There's… I can't explain it, but I…”

“I get it.” Nyx wants to hold Ignis's hands in his, to calm their increasingly frantic fidgeting. “And, well, I didn't like it very much, but I also understand your reaction. It was a lot to process in a span of a few minutes. And I'm sorry about springing it on you like that.”

“Apology accepted.” Ignis smiles at him tentatively before saying, “I hope you'd accept mine, too.”

“Yeah, of course.”

They look at each other for a few more heartbeats. Nyx wonders if Ignis could hear the rush of his blood, so loud in his ears it could have been the growl of a Galahdian coeurl.

“So,” Ignis finally says. He clasps his hands behind him and teeters forward on tiptoes, a classic display of nerves that has never looked so elegant. “Why did you want to see me?” 

“Uh, yeah, about that. Um. I'd like to uh… well, ask you out on a date.” He feels awkward, nervous, like he was in fifth grade again and talking for the first time to his crush. 

“I already agreed to go on a date with you, didn't I?” 

Nyx runs his hand on the buzz of his undercut. “Yeah, well, that was before we found out that we're… soulmates.” It feels odd, saying the word out loud. Soulmates. “And it was sort of a contract before, right? So I wanted to ask you out properly without any strings attached.”

Libertus would probably kill him, and Crowe would say “The fuck are you doing?” for giving Ignis an out, but it just feels right to give the man a choice. He hopes Ignis would say yes, though.

“Well…” Ignis says with a clearing of his throat and Nyx panics.

“I'll still take over your weapons training, if that's still what you want. But the date's a stand-alone thing. You can say no to the date and I'll --”

“Yes.”

“What?” He’s hoping for it but isn't expecting it, so the word stuns Nyx for a bit.

Ignis laughs. “Yes, I'd like to go on a date with you. Get to know you better, while we're at it.”

“Getting to know me better will take more than one date, you know,” Nyx says. There's a feeling of giddiness flooding his system, and it makes his usual confidence seep through.

“Well, then you have to make the first date worth my while, haven't you?”

“How about tomorrow night at seven? We can meet at the welcome arch of Little Galahd.” Nyx knows Ignis already said yes, but he still mentally crosses his fingers.

“Sure. I'd love that.”  


⁂

  
It takes three months -- the time it took for them to finally indulge the insistent, persistent urge of their bodies -- for Nyx to realize that his, no _their_ soul marks have changed.

“Why is your soul mark…” he struggles to find a word. “Faded?”

“What do you mean?” 

He runs a finger on the swirls of flame and lightning. “It's… well, it's supposed to be black, right? Or a deep gray. Yours looks… I can't tell by the light, but it looks a little more blue to me.” Like the color of my eyes, he adds quietly in his head. 

“Oh,” Ignis says, and it's not in surprise but in understanding. “Turn around for me, please.”

Nyx does so without question, and he shivers when Ignis presses a kiss to his soul mark. “Did mine fade, too?”

“Of a sort.” Ignis says softly. “It's green now.”

The words make Nyx's heart clench, as if his body is reacting to that strange sensation of being tugged closer and closer to someone else.

He turns again to face Ignis to kiss him, and he swears he could feel their souls intertwine.  



End file.
